Some driver circuit applications are directed to providing a driving current, such as for groups of light-emitting diodes (LEDs). The number of LEDs may vary depending on the specific application. A driver may control the current flowing through the LED chain, while the output voltage may be set by the number and the forward voltage of the LEDs that compose the chain. In many applications, it is desirable for the driver to deliver a constant average current (as opposed to, e.g., a constant voltage) through the load when the load is switched on. Many driver circuits typically use an external capacitor to measure the output current, to help ensure that the output current is maintained at a specified value.